Design help and advise for radial woodhorn

[Flemming Skov]

Hi forum,

I'm have build a corner horn equipped with JBL units (K145, 2445, 2404) and jbl 2397 for midrange.

You can see the pictures here : http://www.hifi4all.dk/forum/forum_p...TID=33192&PN=3 but, sorry, it's on danish. There is 7 folders, with some pictures. But anyway, my questions are:

Has somebody played with the wood radial horn ala TAD and Fostex (see the link for what I'm considering, http://www.fostexinternational.com/d...ial-Horn.shtml) , the H200 horn (fn 240 Hz).

The advise I need is the exponential curvature to construct after. Or the math. to do the curve. Anybody here who has some experiance in that?

I have used the jbl2397 mid horn but find that, for the cornerhorn it is nescessary to go even below 500 Hz. First I have done some new "finns" to build a biggere 2397 a like horn but the radial horn came accross.

Another question. Is it possible to drive the jbl2445 below 500 Hz (my point is 250 Hz). I use 24 dB/oct. filters. Is it possible to get an output or is it to low compared with the spl above 500 Hz?

Looking forward to here any comments

Regards
Flemming

[Mr. Widget]

Why not buy the Fostex horn? They are surprisingly affordable. They will not do what you want though. A horn with a 240Hz cut off should be used with a crossover no lower than 480Hz.

You will also need a different driver like one of the phenolic diaphragmed JBLs and a radial that can get that low is huge. The JBL 2356 in these links is a radial design that is rated for use down to 300Hz. It is a real monster.

http://www.lansingheritage.org/image...pro/page18.jpg

http://www.lansingheritage.org/image...pro/page19.jpg


Widget

[Flemming Skov]

They are not affordable! 1100$ for maybe 2 but I think it's for one!!

Yes, I do agree that they are really big. But that is if the "stuff" should go for the open field stadium. In my living room I think that placement close to a corner will extend the response.

Here is a picture of the horn Art Of Sound uses for there cornerhorn. The physical measurements are 76 cm wide, 18 cm high and 39,8 cm deep.
http://eckhorn.bonifa.net/Hornlautsp...n_Standard.php

Here the price is 900€ for 2 pieces. They uses Selenium drivers.

Reg.
Flemming

[Mr. Widget]

They are not affordable!

I guess affordable is a sliding scale.... also, I believe they are less expensive over here.

Anything smaller than that huge JBL will be a compromise that I wouldn't make... but as we've said before, in loudspeaker design it is all about juggling the compromises.


Widget

[yggdrasil]

Last year I did some work on radial wood horns. Designed this tractrix with a Fc of ~400Hz. Used from 750. Made a spreadsheet for transforming from round tractrix to radial.

If you like, I can send you the spreadsheet, basic drawings and how-to.

[rs237]

hello,

owing to the assistance of some forum members I was to be built in a the position a pair A300 horns. If interest exists can I still further pictures show if the horns is completely finished. Apology for my bad English, is from on-line translater.

regards juergen